A conventional control device, which controls the operation of a combustion system including an internal combustion engine, controls the injection amount and injection timing of fuel, an EGR amount, a supercharging pressure, and the like so as to output a desired power while keeping, for example, exhaust emission and a fuel consumption rate within appropriate ranges.
The properties of fuel to be supplied to a combustion system, such as, for example, the dynamic viscosity, density, volatility, ignitability, and the like of the fuel, differ depending on the mining location, refinery location, and the like of the fuel. If the properties of fuel are different, optimal control contents also differ. Therefore, a technique is conventionally known in which the dynamic viscosity of fuel is detected by a dynamic viscosity sensor such that the control contents are corrected in accordance with the detection result.
However, the components contained in fuel differ from fuel to fuel, and the mixing ratios of the various components also differ from fuel to fuel. For example, the components contained in fuel and the mixing ratios of the components differ depending on the mining location, refinery location, and the like of the fuel, such as fuel containing a large amount of aroma components and fuel containing a large amount of paraffin components. Therefore, even if fuel has the same value detected by a dynamic viscosity sensor, the components contained in the fuel may actually differ or the mixing ratios of the components may actually differ. Therefore, in a conventional method of changing a control content in accordance with the results detected by a dynamic viscosity sensor, there is a limit to the implementation of optimal control in accordance with fuel.